PROJECT SUMMARY/ABSTRACT Breast cancer is a major global health problem requiring strategies for capacity building. Its incidence is increasing and low- and middle-income countries (LMIC) are being disproportionately affected. Africa suffers the greatest burden of breast cancer with the highest age-standardized mortality rates in the world. The cause of this disparity is multifold. One major barrier in LMIC is the lack of affordable and appropriate breast cancer diagnosis by ultrasound (US)-guided biopsy. While it is the standard of care in high-income countries (HIC), it is not performed by radiologists in LMIC despite the Breast Health Global Initiative?s recommendation. Most radiologists in LMIC do not have the required skills to perform US-guided breast biopsy; hence, breast cancer is often diagnosed by blind biopsy or surgical excision. Until recently, the prohibitive cost of US devices limited their availability in LMIC. US is the mainstay of diagnostic imaging in LMIC and so they are in near constant clinical use and not available for capacity building. New technologies have overcome this barrier because mobile health (mHealth) US-devices are now FDA approved products, which are the perfect low cost alternative. These hand- held, battery operated point-of-care (POC) mhealth US devices offer a safe, simple and sustainable solution. The gap in LMIC affordable and appropriate breast cancer diagnosis is no longer technology, equipment, infrastructure or staff but the lack of an established US-guided breast biopsy-training program. Therefore, the goal of our proposal is building scalable US-guided breast biopsy capacity. In Aim 1, we will develop a competency-based mHealth US-guided breast biopsy-training program for LMIC radiologists and validate the assessment metrics. In Aim 2, we will train ten ARGO Nigerian radiologists to perform US-guided breast biopsies using the competency-based mHealth training program. ARGO (The African Research Group for Oncology) is a network of physicians and hospitals that have already demonstrated success in breast cancer research with a focus on early detection and committed to participating in this project. Our proposal includes a preexisting, successful clinical research team in the USA and Nigeria who are studying breast cancer together and have pioneered the feasibility of tablet-based mHealth US-guided breast biopsy training and clinical implementation in Nigeria. The significance and innovation of this proposal lies in establishing the critical role of mHealth in building a POC US-guided breast biopsy training program for LMIC that: 1) enables affordable and appropriate breast cancer diagnosis, 2) is scalable to other LMIC and HIC and 3) can be adapted for other image-guided procedures that could also impact global cancer control through diagnosis, therapeutic intervention and/or palliation.